Tetrahydro-4H-pyran-4-one → methyl 5-bromo-2-methyl-3-((tetrahydro-2H-pyran-4-yl)amino)benzoate

Participants

Reaction Steps

To a stirred solution of methyl 3-amino-5-bromo-2-methylbenzoate (40.2 g, 165 mmol) in CH2Cl2 (500 mL) and AcOH (60 mL) was added dihydro-2H-pyran-4-one (17.3 g, 173 mmol) and sodium triacetoxyborohydride (73.6 g, 330 mmol). The reaction mixture was stirred at RT for 20 hours. Then saturated NaHCO3 aq. was added and the mixture was separated. The aqueous layer was extracted with CH2Cl2 and the combined organic layer was concentrated in vacuo. The residue was triturated with ethyl ether, and resultant precipitate was collected to afford the titled compound as a white solid (39.1 g, 72%). 1H-NMR (400 MHz, DMSO-d6) δ ppm; 7.01 (s, 1H), 6.98 (s, 1H), 5.00 (d, J=7.6 Hz, 1H), 3.84-3.87 (m, 2H), 3.79 (s, 3H), 3.54-3.56 (m, 1H), 3.43 (m, 2H), 2.14 (s, 3H), 1.81-1.84 (m, 2H), 1.47-1.55 (m, 2H).

Provenance & Evidence